Octahydrophenanthrene hydroxy lactone and derivatives thereof



fatented Aug. 30, 1949 OCTAHYDROPHENANTHRENE HYDROXY LAo'roNn ANDDERIVATIVES, THEREOF Robert P. Jacobson, Shrewsbury, and Gregory Pincus,Worcester, Mass., assignors to G. D. Searle & 00., Skokie, 111., acorporation of Illinois No Drawing. Application November 2, 1946, SerialNo. 707,536

Claims.

This invention relates to the hydroxy lactone formed by inneresterification of the carboxyl group with one of the hydroxyl groups ofa new dihydroxy acid whose formula is C18H2404 and which contains thesame 2-methyl-7-hydroxyoctahydrophenanthrene nucleus that occurs inestrone, and to lower alkyl ethers and to lower alkanoic acid andbenzoic acid esters derived from said hydroxy lactone. This newdihydroxy acid and the hydroxy lactone derived therefrom areconveniently prepared by the oxidation of estrone as described below,while the salts, ester, and ether derivatives are prepared from the acidor lactone by conventional operations. These new compounds are usefuland valuable in thera-. peutics in that they possess the property ofinhibiting certain secretions of the anterior portion of the pituitarygland, while at the same time being free from any appreciable estrogenicactivity.

The pituitary gland, as the so-called master gland of the body,elaborates and secretes certain hormones which control and stimulate thesecretions of certain other glands, including the ovaries. The ovariesin turn are the source of secretion of the various estrogenic hormones.These estrogenic hormones, in addition to controlling phases of themenstrual cycle and organs of the female reproductive system, also actto inhibit certain phases of the activity of the pituitary gland.forming in this way a self-regulating system of physiological balance.At the time of the menopause, secretion of estrogens by the ovariesceases. As a result, secretions of gonadotrophin (the hormone orhormones which stimulate the activity of the gonads to secreteestrogenic hormones) and other hormones by the pituitary often reachexcessive levels since they are no longer restrained by the presence ofestrogenic hormones. This tends to cause many of the unpleasant andundesirable symptoms frequently associated with the menopause. Theadministration of estrogenic hormone substances is known to control suchsymptoms, at least in part through their pituitary inhibition, but itproduces undesirable estrogenic efiects at the same time. Thus it willbe seen that a substance which will effectively inhibit certainpituitary activity and at the same time not produce estrogenic activityis a useful, valuable, and desirable addition to the field oftherapeutics. It is the object of this invention to provide such asubstance.

V which oxidation product was apparently a iactone in chemicalstructure, and which possessed estrogenic properties, though to a lesserdegree than was possessed by the estrous from which it was derived.Subsequently, (Endocrinology, Vol. 35, page 146; and Proceedings of theSociety for Experimental Biology and Medicine, vol. 59, page 242), theestrogenic nature of this lactone was confirmed and it was shown to actas a more potent stimulant to pituitary activity than estrone itself. Inattempting to prepare the so-called Westerfeld lactone to betteradvantage than previously described, Mather discovered that estronecould be oxidized by hydrogen peroxide in glacial acetic acid to yieldwhat appeared at that time to be Westerfelds lactone, which process isthe subject of a now abandoned copending application of Alan Mather,Serial No. 610,203, filed August 10, 1945. Working with a modificationof Mathers process, we have now found that the A isdissolved in about 8parts by weight of glacial acetic acid, and about 6 parts by weight of acommercial 30 per cent aqueous solution of hydrogen peroxide is added.The mixture is maintained at about 35 centigrade for from 55 to hours,at the end of which time water is gradually added until crystallizationof the product is complete. The reaction may be carried out at othertemperatures in the range from 25 C. to 60 0., though it will beapparent to one skilled in the art that at higher temperatures the timeof reaction must be appropriately reduced, and at lower temperatures thereaction period must be suitably extended. The crude crystals (meltingpoint 144 (IL-148 C.) as obtained above are best purified by CHaC O O-The clear filtrate is made acid to Congo rediami the resultingsuspension is warmed to complete formation of the lactone from thedihydroxy acid as first precipitated. The solid lactone is thencollected, washed with water, andfafter thor- I ough drying, isacetylated with acetic anhydride, in pyridine solution. The pure acetoxylactone, which is believed to have the formula ie A) erfelds lactonesuggests the possibility that the difference between the two compoundsmay lie in the arrangement of groups about one or more of the asymmetriccarbon atoms of the molecule, thopgh this has not been established asfact, and the value and efficacy of this invention are in no waydependent upon the ultimate accuracy of such a speculation.

Stated abpye, the lactone of the dihydroxy acid of our inventionexhibits a free phenolic hydroxyl group which can be readily esterifiedwith a variety of organic acids by the application of conventionaltechniques of organic chemistry. For instance, warming of the purehydroxy lactone in pyridine solution with acetic anhydride yields theacetoxy compound (CH2404) described above. Similarly, use of propionicanhydride I leads to ,the propionate (C21H2604, melting point 146-148.5C.) and benzoyl chloride leads to the Fon I 1 -cmcmeoon meitsatrzzs c.with-decomposition, andiis somewhatunstable, Showingelk-marked tendencyto lose one molecule of water through inner e's'teri-fication of on'e ofits hydroxyl groups by the 'arboxyl group to yield a stable monohydroxylactone, which is believedto have the formula This hydroxy lactone maybe purified byprystalli'zati'on ifrom-cyclohexanone or methylceil'osolve, and'when pur melts ares's' 'c. Elementary analysis;'sho wsthat it'h'as the momposition. Qrsrl Qs. so that it'is' isomeric with thecompound obtained by .Wester'feld. It. contains an l ydroxyl group, asshown below by its ability to ;form esters and ethe'rs'. This hydroxyl.group is phenolic in nature (as in estrone) :since, after -thelactoneijing is op erred by treatment with sodium hydroxide, the coihpoundformsaxiisodiu'm salt (one, sodium on the carboxyl'group created by, openingthe lactone ring and ume on -thephenolic hydroxyl group) Thydroxylgroup-formed*iir pening the lactone ring isaicoholicinnature,:and probab1y;teiftiary. 'ihesimilarity of 'chemicarpropertieswith Westbenzoate (C25H2 604, melting point 241-243 C As is readilyapparent, other organic acids, both menobasic and polybasic, may be usedto form the corresponding esters.

The phenolic hydroxyl group of this lactone of the dihydroxy acid of ourinvention can also be ethe-rified by treatment of a warm aqueousalkaline solution of the hydroxy lactone with an alk'ylating agent, suchas dimethyl sulfate. During such treatment, the lactone ring is opened(the compound in such aqueous allialine solution is inf-act the disodiumsalt of the corresponding dihydroxy acid) ,and upon-acidification of thereaotion mixture the monomethy-l ether (0191-12604, melting point 135136" C. with decomposition) of this dihydroxy acid is obtained. Heatingof the acidified reaction mixture causes reformation or the lactone ringand the -methoxy lactorie (C1sHz4a,-mel-ting point .-l72.5-?-1'74 C.) isobtained. The use ofotheralkylating agents with the hydroxy lactone,such as methyl iodideand silver oxide, lead to the formation of themethyl ether directly. Other alkyl sulfates halides, and the like may-ofcourse be used-to produce different alkoxy derivatives. Westerfeldreported a melting-.pointof 1 66-168 -C. forthe methyl ether of liiseompound.

I he monosodium salt of-the dihydroxy acid of our invention may beobtained by saturating a cool alkalihe solution of the acid (mostreadily prepared by hyd'rolyzing the hydroxy lactone in an lexeess ofalkali) with carbon dioxide. After concentration -of the solution, thedesired monosodiurri salt crystallizes, and can be purified bycrystallization'frpm ethanol. It occurs as thin needles-Which meltrat-285C with decomposition. This salt: (andothers'which may besimilarly prepared) is-watersolubleandthus constitutes a de sirablemeansof-preparing the compounds of this inventionior therapeuticadministration in water solution. "A-s stated above, the 'free dihydroxyacidicigfizioi) -is obtained by careful acidification of theSodiur'n-salt' without relactonization.

"Treatment of-the dihydroxy acid with diazomethane yields a d'ihydrcx-ymethyl ester (CiiiHsOii%Hz,;meltingpoint -97 C.) Similarly, treatment ofthe monomethyl ether, of the dihydroxy acid (described above) with diazomethane-yieldsthe methyl ester (0203 804, melting'gioint ifa 'iil" 0;.)of the monomethyl ether of thedihydroxy acid.

'Wh'lIe 'there have been described above the preparat nd ce ain. p ortie p a numb or-a v r .Q I'Il ew dih rox ampu e invention, we;havefolindthat amongthese compounds thdihydroxy acid itself an'd'certain ofits salts, esters, and ethers are preferred forms of this invention,primarily because of their relative superiority for therapeutic use andphysiological activity. For this reason most of the work indemonstrating the novel physiological properties of the compounds ofthis invention has been done with the dihydroxy acid and itsderivatives.

The differences between both the lactonized and unlactonized derivativesof the dihydroxy acid as prepared and described in this invention andthe lactone of Westerfeld may best be recognized by the followingdifferences in their physiological properties:

1) While the estrogenic activity of the saponified lactone of Westerfeldis less than that of estrone it is nonetheless a fairly potent estrogen.In contrast, the dihydroxy acid of our invention exhibits not more than/100 of the estrogenic activity of estrone and many of the derivativesof this acid exhibit considerably less estrogenic activity than theparent acid.

(2) The saponified lactone of Westerfeld stimulates the secretion ofgonadotrophin (especially luteinizing hormone) from the pituitary gland;the dihydroxy acid of our invention and its derivatives not only fail tostimulate such secretion, but inhibit it.

(3) The saponified lactone of Westerfeld stim ulates the secretion ofcorticotrophin by the pituitary gland; the dihydroxy acid of ourinvention and its derivatives do not so stimulate the pituitary gland.

(4) The saponified lactone of Westerfeld greatly increases the responseof immature female rats to injections of follicle stimulating hormone;the dihydroxy acid of our invention and its derivatives produce no suchaugmented response.

It is thus quite apparent that, while such conventional properties asmelting points and solubilities are somewhat similar for the threelactone derivatives produced by Westerfeld and the correspondinglactonized derivatives of the dihydroxy acid of this inventionnonetheless the compounds cannot be identical, for if they were, theycould not have such widely differing physiological properties.

The invention is defined by the appended claims.

The subject matter relating to the dihydroxy acid derivatives is claimedin our divisional application Serial No. 79,108, filed March 1, 1949.

We claim:

1. As new chemical compounds, members of the group consisting of thephenolic hydroxy lactone which contains the same2-methyl-7-hydroxyoctahydrophenanthrene nucleus that occurs in estrone,which has the formula Ciel-12203, and

which has a melting point of about 339 C., and the lower alkyl ethersand lower alkanoic acid and benzoic acid esters derived from the7-hydroxyl group of said hydroxy lactone, all of which compounds arefurther characterized by exhibiting not more than approximately of theestrogenic activity of estrone and by inhibiting the secretion ofgonadotrophin by the pituitary gland.

2. As new chemical compounds, lower alkanoic acid esters of the phenolichydroxy lactone of the formula C18H22O3 having a melting point of about339 C. and containing the same 2-methyl-7-hydroxyoctahydrophenanthrenenucleus that occurs in estrone, said lower alkanoic acid esters beingfurther characterized by exhibiting not more than approximately /100 theestrogenic activity of estrone and inhibiting the secretion ofgonadotrophin by the pituitary gland.

3. As a new compound, the acetate of the phenolic hydroxy lactone of theformula C18H2203 having a melting point of about 339 C. and containingthe same Z-methyl-7-hydroxyoctahydrophenanthrene nucleus that occurs inestrone, said acetate melting at 149-1515 C., having a rotation of [a]=|-4:2 in chloroform, exhibiting not more than /100 of the estrogenicactivity of estrone and inhibiting the secretion of gonadotrophin by thepituitary gland.

4. As a new compound, the methyl ether of the phenolic hydroxy lactoneof the formula CmHzzOa having a melting point of about 339 C. andcontaining the same 2-methyl-7-hydroxyoctahydrophenanthrene nucleus thatoccurs in estrone, said methyl ether melting at 1'72.5-174 0.,exhibiting not more than /100 of the estrogenic activity of estrone andinhibiting the secretion of gonadotrophin by the pituitary gland.

5. As a new compound, a phenolic hydroxy lactone having the formulaC1sH22O3 and having a melting point of 339 C., which contains the same2-methyl-7-hydroxyoctahydrophenanthrene nucleus that occurs in estrone,which compound is further characterized by exhibiting not more thanapproximately /100 of the estrogenic activity of estrone, and byinhibiting the secretion of gonadotrophin from the pituitary gland.

ROBERT P. JACOBSEN. GREGORY PINCUS.

REFERENCES CITED The following references are of record in the file ofthis patent:

Westerfeld, Jour. Biol. Chem, vol. 143, pp. 177- 184, 1942.

Endocrinology, vol. 35, page 146 (1944).

Certificate of Correction August 30, 1949 Patent No. 2,480,246

ROBERT P. JACOBSEN ET AL.

. It is hereby certified that error appears in the printed specijicatinumbered patent requiring correction as follows:

Column 4, line 38,1 for C I-1 10 read C H 0 and that the said LettersPatent should be read with this correction therein that the the case inthe Patent Office.

same rnay conform to the record of slgned and sealed this 17th day ofJanuary, A. D. 1950.

on of the above THOMAS F. MURPHY,

Assistant Commissioner of Patents.

